WORDS EMILY PRITCHARDWomen’s Health SEPTEMBER 2019 | 39
Thanks to talk of swerving
dairy and the ubiquitous
self-diagnosed gluten bloat,
mention of allergies is more
often than not written off
with a side-eye. But there’s
scores of science to show that
allergies are on the rise. On a
topic with more questions than
there seem to be answers, let
us slice through the confusionrying to remember
precisely when the
panic set in is difficult.
The first signs took
the form of tiny hazard
symbols, peppered
across the menus of restaurants and
cafes. The nutritional equivalent of a
skull and crossbones, they outed a dish
for containing something dangerous,
potentially; an ingredient wisely
avoided. As minuscule shafts of wheat
signposting gluten and scaled-down
milk bottles signalling lactose became
commonplace, anecdotal dietary
preferences and food intolerances
swiftly became reported as allergies.
While smear campaigns abounded
against gluten, dairy and caffeine – and
medical professionals swiftly stood to
attention to explain that IBS-like
symptoms don’t always equal a legit
allergy – official statistics have confirmed
that we should all be paying heed to
a spike in bona fide negative reactions.
Q
WHAT IS AN ALLERGY?
‘An allergy is an abnormal
immune reaction,’ explains
Professor Graham Roberts, consultant
in paediatric allergy at the University of
Southampton. ‘The human body is set up
to fight infections, such as harmful bacteria
and viruses – prepping specialist cells in
your bloodstream with antibodies primed
to disarm disease – but sometimes the
immune system recognises food sources
as a potential danger, and over-responds.’
Take the peanut. ‘Peanuts are a completely
innocent protein and shouldn’t cause the
body any harm,’ says Professor Roberts.
And yet, one study estimated that 1.76% of
the UK population are anaphylaxis-level
allergic to tree nuts. ‘When the immune
system’s cells recognise, for example, the
peanut protein, they release inflammatory
mediators, such as histamine,’ continues
Professor Roberts. ‘In small amounts,
histamine leads to the symptoms we might
associate with hay fever – a runny nose,
sneezing, itchy eyes and a rash. In large
quantities, the mediators flood the body,
and it’s this that, in some cases, leads to
constriction of the airways to the extent
that sufferers can’t breathe.’ This, combined
with dilated blood vessels, he explains,
renders transportation of oxygen to major
organs impossible. It can be fatal.Q
ARE THEY REALLY
ON THE RISE?
It would appear so, and, in the
UK, the increase began much earlier than
for the majority of the world. In the 20
years between 1992 and 2012, UK hospital
admissions for anaphylaxis skyrocketed by
615%, with the rates of peanut allergy alone
doubling. Figures from Allergy UK show
that there’s a staggering 44% allergy rate
among British adults, though just under
half registered were medically diagnosed,
rather than self-reported. And then there’s
the estimated 7.1% of breastfed infants who
have food allergies – more than double the
rate in adults. It’s a rapid escalation, even
taking into account that some babies will
outgrow their allergies. Each new generation,
their food becoming inexplicably deadly,
seems to be in greater danger than the last.Q
WHY THE ESCALATION?
Theories abound. One blames
a fall in breastfeeding rates,
referencing studies that link breastfed
babies with lower rates of allergic diseases.
It’s thought that introducing allergens in
breast milk may help to develop tolerance- but the connection is far from proven.
‘There are lots of benefits to breastfeeding,
but no definitive evidence that it prevents
allergies,’ explains Professor Roberts.
Another, more likely, theory? The hygiene
hypothesis. ‘The human immune system
has developed over hundreds and thousands
of years in line with how we live, but we’ve
turned our way of life around within the
past century; food is cooked, water is clean,
everything is disinfected. There are barely
any microbes in the environment, which
means the immune system doesn’t get
the same balance your ancestors evolved
to deal with.’ The upshot? According to
Professor Roberts: ‘As we develop in the
21st century, we think that the immune
response starts to attack non-harmful
stimulants.’ Like eggs, nuts and milk.
‘In the most developed countries, where
allergy rates started going up much earlier
than in the majority of the world, they’re
probably starting to stabilise,’ says Professor
Roberts. In other words, we’ve reached peak
clean, and for those consequently spending
their lives beholden to an EpiPen, their fate
is sealed. Meanwhile, Professor Roberts
predicts that allergy rates will continue to
soar elsewhere in the developing world.
Q
WHO’S MOST AT RISK?
Interestingly, no one is born
with a food allergy. ‘In order for
an allergy to develop, your body needs to
be exposed to the allergen,’ says Professor
Roberts. Although, there are food allergies
where a genetic predisposition seems to
come into play; there’s a seven-fold risk
of developing an allergy to peanuts, for
example, if a parent or sibling also suffers.
‘It’s a combination of hereditary and
environmental factors,’ says Professor
Roberts – and the genes play a large role,
with the research suggesting that they
account for around 80% of the risk. Often,
children who suffer from skin disorders,
such as eczema, show more vulnerability.
‘We think that when the damaged skin
barrier is exposed to an allergen – maybe on
the hands of a parent or by touching a food- the immune response is primed, so when
the child first eats the food, the immune
system quickly responds in the form of an
allergic reaction,’ says Professor Roberts.
‘Usually, if they eat the food first, they’ll
develop tolerance.’ As for adulthood onset?
‘The bottom line is, we just don’t know,’
says Professor Roberts – although it’s an
area of rapidly expanding research.
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